Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS7655090 B2
Publication typeGrant
Application numberUS 11/855,785
Publication dateFeb 2, 2010
Filing dateSep 14, 2007
Priority dateAug 4, 2000
Fee statusPaid
Also published asEP1307903A1, EP2276059A1, US7687888, US7816764, US8525230, US20020020341, US20080102610, US20090242898, US20110108886, US20120068191, WO2002013245A1
Publication number11855785, 855785, US 7655090 B2, US 7655090B2, US-B2-7655090, US7655090 B2, US7655090B2
InventorsHugues Marchand, Brendan Jude Moran
Original AssigneeThe Regents Of The University Of California
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method of controlling stress in gallium nitride films deposited on substrates
US 7655090 B2
Abstract
Methods of controlling stress in GaN films deposited on silicon and silicon carbide substrates and the films produced therefrom are disclosed. A typical method comprises providing a substrate and depositing a graded gallium nitride layer on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply. A typical semiconductor film comprises a substrate and a graded gallium nitride layer deposited on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply.
Images(10)
Previous page
Next page
Claims(16)
1. A method of producing a semiconductor film, comprising:
providing a substrate; and
depositing a graded gallium nitride layer on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition and a net compressive stress, formed from a supply of at least one precursor in a growth chamber without any interruption in the supply.
2. The method of claim 1, wherein the step of depositing the graded gallium nitride layer comprises using metalorganic chemical vapor deposition (MOCVD).
3. The method of claim 1, wherein the step of depositing the graded gallium nitride layer comprises changing a vapor pressure of the supply of at least one precursor in a growth chamber for the graded gallium nitride layer.
4. The method of claim 1, wherein the precursor is gallium, aluminum or nitrogen.
5. The method of claim 1, wherein the step of depositing the graded gallium nitride layer comprises changing a parameter of the growth chamber for the graded gallium nitride layer.
6. The method of claim 5, wherein the parameter of the growth chamber is a total pressure, a temperature of the substrate, a total flow, a rate of substrate rotation or a reactor wall temperature.
7. The method of claim 1, wherein the step of depositing the graded gallium nitride layer comprises changing the geometry of the growth chamber for the graded gallium nitride layer.
8. The method of claim 7, wherein changing the geometry of the growth chamber comprises moving the substrate relative to injectors of the growth chamber.
9. The method of claim 1, wherein the substrate is silicon or silicon carbide.
10. The method of claim 1, wherein the initial composition comprises substantially at least a 20% aluminum composition.
11. The method of claim 1, wherein the initial composition is aluminum nitride or a high aluminum content aluminum gallium nitride where the aluminum content comprises substantially at least 20%.
12. The method of claim 1, wherein the final composition comprises substantially less than a 20% aluminum composition.
13. The method of claim 1, wherein the final composition is gallium nitride or a low aluminum content aluminum gallium nitride where the aluminum content comprises substantially less than 20%.
14. The method of claim 1, further comprising depositing at least one additional layer on the graded gallium nitride layer.
15. The method of claim 1, wherein the step of forming the graded gallium nitride layer comprises introducing at least one other element into the growth chamber for the graded gallium nitride layer causing no abrupt variations in the varying composition of the graded gallium nitride layer.
16. The method of claim 15, wherein the other element is silicon, indium or arsenic.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of United States Utility Patent Application Serial No. 09/922,122, filed Aug. 3, 2001, by Hugues Marchand and Brendan J. Moran, and entitled “METHOD OF CONTROLLING STRESS IN GALLIUM NITRIDE FILMS DEPOSITED ON SUBSTRATES,” which application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 60/222,837, filed Aug. 4, 2000, by Hugues Marchand and Brendan J. Moran, and entitled “METHOD OF CONTROLLING STRESS IN GAN FILMS DEPOSITED ON SILICON AND SILICON CARBIDE SUBSTRATES,” both of which applications are incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with Government support under Grant No. N00014-98-1-0401, awarded by the Office of Naval Research. The Government has certain rights in this invention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to nitride films, and particularly methods to reduce the formation of cracks in gallium nitride films for semiconductor devices.

2. Description of the Related Art

(Note: This application references a number of different publications as indicated throughout the specification by reference numbers enclosed in brackets, e.g., [x]. A list of these different publications ordered according to these reference numbers can be found below at the end of the Detailed Description of the Preferred Embodiment. Each of these publications is incorporated by reference herein.)

The deposition of GaN films on silicon substrates is difficult because of a large thermal expansion coefficient mismatch between the two materials. Most deposition techniques involve the deposition of buffer layers or stress-relief layers with a distinct composition from that of the substrate and that of GaN; there is an abrupt composition variation between the buffer layer and the GaN layer. These techniques result in GaN films which are under tensile stress at room temperature. Tensile stress favors the formation of macroscopic cracks in the GaN, which are detrimental to devices fabricated thereon.

GaN and its alloys with InN and AlN are used in visible or UV light-emitting devices (e.g. blue laser diodes) as well as high-power, high-frequency electronic devices (e.g. field-effect transistors). Because of the lack of GaN substrates, such devices are typically fabricated from a thin layer of GaN deposited on a substrate such as sapphire (Al2O3) or silicon carbide (SiC). Although both substrates are available in single-crystal form, their lattice constant is different than that of GaN. This lattice mismatch causes extended defects such as dislocations and stacking faults to be generated at the interface between the substrate and the GaN layer as well as into the GaN layer itself. The use of buffer layers such as AlN or low-temperature GaN and the optimization of deposition conditions typically yields films with approximately 109 threading dislocations per square centimeter. More novel techniques such as lateral epitaxial overgrowth (LEO), “pendeoepitaxy,” and maskless LEO result in lower dislocation densities (as low as 106 cm−2).

Although GaN-based devices are currently being mass-produced using both sapphire and silicon carbide substrates, the use of silicon substrates is expected to bring about further cost reductions as well as improvement to the capability of those devices. For example, silicon can be etched using simple chemicals, which allows simple substrate-removal techniques to be utilized with GaN-based films or devices. Silicon is also the material on which most of the electronic devices (e.g. microprocessors) have been developed; integrating GaN-based devices with silicon-based electronic functions would create new types of systems. Silicon is readily available in large wafer sizes with excellent crystal quality at low cost, such that devices grown on silicon may be less expensive than equivalent devices grown on sapphire or silicon carbide. Finally, silicon is a better thermal conductor than sapphire.

The growth of GaN on silicon substrates presents similar challenges as on sapphire and silicon carbide. The lattice mismatch between the (001) plane of GaN and the (111) plane of silicon is 17.6%, compared to 16% for sapphire and 3.5% for silicon carbide. The use of a thin AlN buffer has yielded GaN films on Si(111) with as low as 3×109 threading dislocations per square centimeter. However, the thermal expansion mismatch of GaN with silicon is +31%, compared to −26% for sapphire and +17% for silicon carbide. (The positive sign indicates a thermal expansion coefficient larger for GaN than for the substrate.) Assuming for the sake of demonstration that the GaN film is stress-free at the growth temperature (typically 1000 degrees centigrade), a positive thermal expansion mismatch would result in a GaN film under tensile stress after cool-down to room temperature. GaN films exhibit cracking when the tensile stress exceeds approximately 400 MPa. Cracks generally render devices inoperable due to electrical shorts or open circuits. In general the stress associated with the lattice mismatch, including any relaxation effect that may occur during growth, is referred to as “grown-in stress”. The stress arising from the thermal expansion mismatch when the film is cooled from the growth temperature to room temperature is referred to as “thermal stress”. The sum of the grown-in stress and thermal stress is the net stress in the film.

Several methods of forming GaN films on silicon substrates have been suggested. Takeuchi et al. [1] propose a buffer layer composed of at least aluminum and nitrogen, followed by a (GaxAl1-x)1-yInyN layer. Based on technical papers published by the same group (e.g. [2], [3]) the resulting films are under tensile stress, as can be assessed by photoluminescence spectroscopy measurements. The films exhibit cracking. Extensive work at the University of California, Santa Barbara (UCSB) resulted in significant improvements in crystal quality using this method; however the GaN films were always found to be under tensile stress (200-1000 MPa), which usually caused cracking. Takeuchi et al. [4] also propose 3C—SiC as a buffer layer. The resulting GaN films also exhibit cracking, which is strong evidence that they are under tensile stress. Yuri et al. [5] propose an extension of this method wherein the silicon substrate is chemically etched after the deposition of a thin layer of GaN on the SiC buffer layer, such that subsequent deposition of GaN is made possible without the tensile stress problems, associated with the presence of the silicon substrate. Marx et al. [6] propose the use of GaAs as an intermediate layer. Shakuda [7] proposes a method of forming GaN-based light-emitting devices on silicon wafers on which a silicon nitride (Si3N4) layer has been deposited.

In all the aforementioned techniques, there is a finite composition step between the substrate and the buffer layer as well as between the buffer layer and the GaN layer. The difference in composition is associated with a difference in lattice constants which, in general, means that a certain amount of elastic energy is present in the layers. The elastic energy is stored in the form of compressive strain if the (unstrained) lattice constant of the top layer is larger than that of the bottom layer. The elastic energy is maximized if the top layer grows pseudomorphically on the bottom layer, that is, if the top layer adopts the in-plane lattice constant of the bottom layer. For the cases under discussion the amount of elastic energy may exceed the energy required to form defects such as islands or dislocations, which reduce the energy of the strained layer. This is especially true if the growth is interrupted, because in general growth interruptions allow a coherently strained layer to evolve into islands. In this case the elastic energy stored in the top layer is reduced compared to the pseudomorphic case.

There is a need for methods of reducing the formation of cracks in gallium nitride films for semiconductor devices. Accordingly, there is also a need for such methods to produce compressive, rather than tensile, stresses in the films. There is further a need for methods to produce such films on common substrates such as silicon. The present invention meets these needs.

SUMMARY OF THE INVENTION

Methods of controlling stress in GaN films deposited on silicon and silicon carbide substrates and the films produced therefrom are disclosed. A typical method comprises providing a substrate and depositing a graded gallium nitride layer on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply. A typical semiconductor film comprises a substrate and a graded gallium nitride layer deposited on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply.

The present invention comprises a deposition sequence that results in the formation of crack-free device-quality GaN layers on silicon substrates using metalorganic chemical vapor deposition (MOCVD). The GaN films grown using the method of the present invention are under compressive stress, which eliminates the tendency of GaN to crack. The deposition sequence consists of a continuous grade from a material A which has a high aluminum composition (e.g. AlN, Al0.5Ga0.5N) to a material B which has a low aluminum composition (e.g. GaN, Al0.2Ga0.8N) over a thickness which constitutes a significant fraction (e.g. 20-100%) of the total thickness of the film being grown. The grade can be accomplished by variety of methods, such as (i) changing the vapor pressure of precursors in the growth chamber; (ii) changing other parameters of the growth chamber such as substrate temperature; or (iii) changing the geometry of the growth chamber. Other elements (e.g. Si, In, As) can also be introduced in the growth chamber such that intermediate materials other than AlGaN are deposited, as long as the composition variations are not abrupt. Other layers can be deposited on the graded layer such that electronic devices (e.g., field-effect transistors) and optoelectronic devices (e.g., light-emitting diodes) are formed, in accordance with common practice in the field. Alternatively, additional layers of GaN or AlGaInN alloys with thickness exceeding five micrometers can also be deposited on the graded layer as a means of forming a free-standing GaN substrate. The method can also be used to control the stress in GaN films grown on silicon carbide (SiC) substrates.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers represent corresponding parts throughout:

FIG. 1 is a schematic cross-sectional view illustrating the structure of the layers fabricated according to the general principles of this invention;

FIG. 2 is an optical micrograph showing the surface morphology of a graded layer (AlN to GaN) deposited on a Si(111) substrate according to the present invention;

FIG. 3 is a cross-section view based on a transmission electron micrograph (TEM) illustrating the microstructure of a graded layer (AlN to GaN) deposited on a Si(111) substrate according to the present invention;

FIG. 4 is a plan-view micrograph based on an atomic force microscopy (AFM) scan illustrating the surface morphology of a graded layer (AlN to GaN) deposited on a Si(111) substrate according to the present invention;

FIG. 5 is a simplified process flow diagram illustrating the sequence in which precursor chemicals are introduced in the growth chamber according to one example of the present invention;

FIG. 6 is a schematic cross-sectional view illustrating the layers used to fabricate a field-effect transistor (FET) device according to one example of the present invention;

FIG. 7 is a set of characteristic curves illustrating the performance of a field-effect transistor (FET) fabricated according to one example of the present invention;

FIG. 8 is an optical micrograph showing the surface morphology of a graded layer (AlN to GaN) deposited on a 6H—SiC substrate according to the present invention; and

FIG. 9 is an optical micrograph showing the surface morphology of a GaN layer deposited on a 6H—SiC substrate according to a comparative example in the case where a thin AlN buffer is used instead of a thick graded layer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a semiconductor film 100 of the present invention as a schematic cross-sectional view showing the structure of the layers fabricated according to the general principles of this invention. A typical method producing the film 100 comprises combining the buffer layer and the GaN layer into a single deposition step to produce a single graded gallium nitride layer 102 on a substrate 104. During the deposition the composition is varied continuously between an initial composition 106 and a final composition 108, without any interruption in the supply of precursors 110 to the growth chamber 112. The initial composition 106 is that of a material A suitable for a buffer layer which wets the substrate, for instance AlN or an AlGaN compound with a moderate to high aluminum fraction (e.g. 20% or more). The final composition 108 is that of a material B such as GaN or AlGaN with low aluminum fraction (e.g. less than 20%). The thickness 116 over which the composition grade 114 takes place is a significant fraction of the total thickness 118 being deposited, for example 20 to 80% of a one micrometer-thick film.

The principal feature of the present invention is that the composition is varied continuously between the initial composition 106 and the final composition 108 without any interruption in precursor 110 supply. From ongoing materials studies it appears that the lack of interruption in the growth process prevents the layers with low aluminum content from dissipating the elastic energy associated with the lattice mismatch between material A and material B. Thus a larger amount of compressive strain is present in the layer structure than is found when using other methods. In many cases the compressive stress is large enough to counterbalance the tensile stress induced by the cool-down procedure such that the net stress in the epitaxial layers is compressive. Compressively-strained films do not crack, hence preserving the properties of any device that may have been subsequently deposited and processed.

The grade 114 can be accomplished by a variety of methods known to those skilled in the art, such as (i) changing the vapor pressure 120 of at least one precursor 110 among Ga, Al, and N in the growth chamber 112; (ii) changing other parameters 122 of the growth chamber, e.g. total pressure, substrate temperature, total flow, rate of substrate rotation, temperature of the reactor walls; (iii) changing the geometry of the growth chamber 112, e.g., moving the substrate relative to the injectors, etc.; or (iv) introducing other elements such as Si, In, or As in the growth chamber 112 such that intermediate-materials other than AlGaN are deposited, as long as the composition variations are not abrupt. Other layers can be deposited after the GaN layer such that electronic devices (e.g. field-effect transistor) and optoelectronic devices (e.g. light-emitting diodes) are formed.

The mathematical function relating the composition of the growing films to the thickness or time can be made to assume any suitable functional form with the use of proper process controllers. The simplest case is that for which the composition varies linearly as a function of time; if the flow rates are adjusted such that the rate of deposition remains constant with time, this method would produce a composition varying linearly with thickness, unless segregation effects occur. In other cases, the rate of composition variation could be smaller (or larger) at the beginning and the end of the grade to further tailor the grown-in stress.

A typical embodiment of the grading process uses AlN as the initial composition 106 and GaN as the final composition 108. The composition can be controlled by changing the partial pressure of the gallium, aluminum, and nitrogen precursors (trimethygallium, trimethylaluminum, and ammonia, respectively). In one embodiment, the substrate 104 is Si(111) and the total thickness 118 of the deposited layer 102 is approximately one micrometer. The growth temperature was 1050 degrees centigrade.

FIG. 2 shows an example GaN film of the present invention. The net stress in one example was measured to be 270 MPa (compressive) using a laser deflection measurement. Optical measurements (photoluminescence, Raman) were also performed and confirmed this value. The GaN film 102 was free of cracks, as shown in FIG. 2. The microstructure of the film was of the single-crystal type.

FIG. 3 is a cross-section view based on a transmission electron micrograph (TEM) illustrating the microstructure of a graded layer (AlN to GaN) deposited on a Si(111) substrate according to the present invention. The dislocation density was higher than in state-of-the art films at the onset of growth (>1011 cm−2), but, because of dislocation annihilation reactions, was low enough (109-1010 cm−2) at the surface of the film to enable device demonstrations, and as will become apparent below.

FIG. 4 is a plan-view micrograph based on an atomic force microscopy (AFM) scan illustrating the surface morphology of a graded layer (AlN to GaN) deposited on a Si(111) substrate according to the present invention. The surface morphology was similar to that of the state of the art GaN films grown on sapphire or silicon carbide substrates as indicated by the atomic force microscopy images. When repeating the process for a thinner film (˜0.55 μm) the compressive stress was measured to be 400 MPa. Several embodiments of the grading method are available using the present invention.

FIG. 5 is a simplified process flow diagram 500 illustrating the sequence in which precursor 110 chemicals are introduced in the growth chamber 112 according to one embodiment of the present invention. In the example, the grading process begins with the deposition of silicon on the surface of the heated silicon wafer by use of a suitable silicon precursor, for example disilane (Si2H6) as indicated by the Si grade line 502. The grade to an aluminum-containing alloy, as indicated by the Al grade line 504, is effected by introducing a controlled amount of a suitable aluminum precursor such as trimethyaluminum (TMAl), thus forming an aluminum silicide. The silicon precursor 110 is then progressively removed from the chamber, thus forming a thin film of aluminum. A nitrogen precursor such as ammonia (NH3) is progressively added so as to complete the transition to aluminum nitride (shown by the NH3 grade line 506), after which the sequence continues with the introduction of a gallium precursor (e.g. trimethylgallium, TMGa) shown by the Ga grade line 508.

In another embodiment of the present invention, the initial composition 106 material consists of silicon (deposited on the substrate 104 as discussed above) and the final composition 108 material consists of GaN, but only silicon, gallium, and nitrogen precursors 110 are used such that the formation of an AlN intermediate layer is avoided. As reported by Chu et al. [8] the direct deposition of GaN on Si substrates 104 usually leads to island formation and highly-defected GaN films. However, in the present invention, the formation of islands is hampered because the deposition is not interrupted. Since the lattice mismatch between GaN and Si(111) is only slightly larger than that between AlN and Si(111), this particular deposition sequence leads to the formation of compressively-stressed GaN on Si(111).

FIG. 6 is a schematic cross-sectional view illustrating the layers used to fabricate a field-effect transistor (FET) device 600 according to one example of the present invention. Several such embodiments of the present invention exist wherein additional layers 602 are deposited following the formation of the graded layer 102 on a substrate 104 for the purpose of fabricating specific devices. The example fabrication process consists of a thin (˜0.2<x<˜0.5) AlxGa1-xN or InGaAlN layer 602 deposited on top of the graded layer 102 which ends with a composition of GaN. Following usual processing steps, such as electrode formation, FETs are produced with the present invention having characteristics comparable to state-of-the-art devices fabricated using other substrates.

FIG. 7 is a set of characteristic curves illustrating the performance of a field-effect transistor (FET) device fabricated according to one example of the present invention. The curves represent the source-drain current as a function of source-drain voltage for increasing gate bias in common-source configuration. The saturation current per unit of gate width is 525 mA/mm and the transconductance per unit of gate width is 100 mS/mm.

In another embodiment of the invention, additional layers 602 of GaN or AlGaInN alloys with thickness exceeding five micrometers can be deposited on the graded layer 102 as a means of fabricating free-standing GaN substrates. The silicon substrate 104 can be removed either by chemical etching, mechanical polishing, or by any other means generally in use in the field.

The method can also be applied to growth on silicon carbide substrates 104. It has been demonstrated by other groups that the stress in GaN films grown on silicon carbide using a thin AlN buffer can be compressive for films thinner than approximately 0.7 μm, while films thicker than ˜0.7 μm are generally under tensile stress. [9] One group has reported that films grown using 0.3 μm-thick Al0.3Ga0.7N buffer layers were under small compressive stress (˜250 MPa). [10] Using the same parameters as for the demonstration on Si(111) described above, the present method produced a 0.65 μm-thick GaN film under 950 MPa of compressive stress when grown on a 4H—SiC semi-insulating substrate. The same process applied to a 1.9 μm-thick film grown on 6H—SiC resulted in 815 MPa of compressive stress.

FIGS. 8 and 9 are optical micrographs comparing results of the present with those of a conventional process. FIG. 8 shows the surface morphology of a graded layer 102 (AlN to GaN) deposited on a 6H—SiC substrate according to the present invention. The graded layer 102 GaN film of FIG. 8 was free of cracks and exhibited a smooth morphology. FIG. 9 is an optical micrograph showing the surface morphology of a GaN layer deposited on a 6H—SiC substrate according to a comparative example in the case where a thin AlN buffer is used instead of a thick graded layer. The stress measured for such a film grown using a thin AlN buffer or a thin grade is typically tensile, on the order of 500 MPa; cracks are present in such films, as shown.

CONCLUSION

This concludes the description including the preferred embodiments of the present invention. The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching.

It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.

REFERENCES

The following references are all incorporated by reference herein:

1. T. Takeuchi, H. Amano, I. Akasaki, A. Watanabe, K. Manabe, U.S. Pat. No. 5,389,571: Method of fabricating a gallium nitride based semiconductor device with an aluminum and nitrogen containing intermediate layer.

2. A. Watanabe, T. Takeuchi, K. Hirosawa, H. Amano, K. Hiramatsu, and I. Akasaki, J. Cryst. Growth 128, 391-396 (1993): The growth of single crystalline GaN on a Si substrate using AlN as an intermediate layer.

3. S. Chichibu, T. Azuhata, T. Sota, H. Amano, and I. Akasaki, Appl. Phys. Left. 70(16), 2085-2087 (1997): Optical properties of tensile-strained wurtzite GaN epitaxial layers.

4. Takeuchi, T. et al., J. Cryst. Growth, December 1991, vol. 115, (no. 1-4): 634-8 .

5. M. Yuri, T. Ueda, T. Baba, U.S. Pat. No. 5,928,421: Method of forming gallium nitride crystal.

6. D. Marx, Z. Kawazu, N. Hayafuji, U.S. Pat. No. 5,760,426: Heteroepitaxial semiconductor device including silicon substrate, GaAs layer and GaN layer #13.

7. Y. Shakuda, U.S. Pat. No. 5,838,029: GaN-type light emitting device formed on a silicon substrate.

8. T. L. Chu, J. Electrochem. Soc. 118, 1200 (1971): Gallium nitride films.

9. N. V. Edwards, M. D. Bremser, R. F. Davis, A. D. Batchelor, S. D. Yoo, C. F. Karan, and D. E. Aspnes, Appl. Phys. Lett. 73, 2808 (1998): Trends in residual stress for GaN/AlN/6H—SiC heterostructures.

10. I. P. Nikitina, M. P. Sheglov, Yu. V. Melnik, K. G. Irvine, and V. A. Dimitriev, Diamond and related materials 6, 1524 (1997): Residual strains in GaN grown on 6H—SiC.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US5192987May 17, 1991Mar 9, 1993Apa Optics, Inc.Gallium nitride and aluminum gallium nitride junction layers
US5239188Nov 4, 1992Aug 24, 1993Hiroshi AmanoSingle crystal of gallium-aluminum-indium nitride; suppresses occurrence of crystal defects; high crystallization; flatness
US5290393Jan 28, 1992Mar 1, 1994Nichia Kagaku Kogyo K.K.Crystal growth method for gallium nitride-based compound semiconductor
US5296395Mar 3, 1993Mar 22, 1994Apa Optics, Inc.Forming a multilayer element with gallium nitride and aluminum gallium nitride layers
US5389571Apr 16, 1993Feb 14, 1995Hiroshi AmanoHolding heated single crystal silicon substrate in atmosphere containing organic aluminum compound and nitrogen compound to form thin film on surface, forming single crystal layers of gallium aluminum indium nitride on intermediate layer
US5393993Dec 13, 1993Feb 28, 1995Cree Research, Inc.Buffer structure between silicon carbide and gallium nitride and resulting semiconductor devices
US5442205Aug 9, 1993Aug 15, 1995At&T Corp.Monocrystalline silicon substrate covered by spatially graded epitaxial layer of germanium-silicon having no germanium at interface, for integrated circuits
US5523589Sep 20, 1994Jun 4, 1996Cree Research, Inc.Conductive silicon carbide substrate; ohmic contact; conductive buffer layer
US5633192Jan 13, 1995May 27, 1997Boston UniversityMethod for epitaxially growing gallium nitride layers
US5679965Nov 9, 1995Oct 21, 1997North Carolina State UniversityContinuously graded layers of aluminum gallium nitride to reduce or eliminate conduction band or valence band offsets
US5741724Dec 27, 1996Apr 21, 1998MotorolaBuffer layers
US5760426Jul 16, 1996Jun 2, 1998Mitsubishi Denki Kabushiki KaishaHeteroepitaxial semiconductor device including silicon substrate, GaAs layer and GaN layer #13
US5786606Dec 12, 1996Jul 28, 1998Kabushiki Kaisha ToshibaSemiconductor light-emitting device
US5815520Jun 21, 1996Sep 29, 1998Nec Corporationlight emitting semiconductor device and its manufacturing method
US5821555Mar 20, 1996Oct 13, 1998Kabushiki Kaisha ToshibaN-type impurity of a higher concentration formed between the first and second layer; lowers the operating voltage; reliability
US5838029Aug 21, 1995Nov 17, 1998Rohm Co., Ltd.GaN-type light emitting device formed on a silicon substrate
US5838706Nov 19, 1996Nov 17, 1998Cree Research, Inc.Low-strain laser structures with group III nitride active layers
US5880485Sep 11, 1997Mar 9, 1999Mitsubishi Denki Kabushiki KaishaAluminum nitride thin layer sandwiched between gallium nitride layers, effective to increase the length of migration of the gallium atoms to form a flat gallium nitride surface layer between the opening
US5880491Jan 31, 1997Mar 9, 1999The United States Of America As Represented By The Secretary Of The Air ForceSiC/111-V-nitride heterostructures on SiC/SiO2 /Si for optoelectronic devices
US5923950Jun 10, 1997Jul 13, 1999Matsushita Electric Industrial Co., Inc.Growing aluminum nitride buffer layer on silicon carbide substrate; growing aluminum gallium indium nitride single crystal layer on aluminum nitride layer
US5928421Aug 26, 1997Jul 27, 1999Matsushita Electronics CorporationMethod of forming gallium nitride crystal
US6039803Feb 27, 1997Mar 21, 2000Massachusetts Institute Of TechnologyUtilization of miscut substrates to improve relaxed graded silicon-germanium and germanium layers on silicon
US6045626Jun 23, 1998Apr 4, 2000Tdk CorporationSubstrate structures for electronic devices
US6051849Feb 27, 1998Apr 18, 2000North Carolina State UniversityGallium nitride semiconductor structures including a lateral gallium nitride layer that extends from an underlying gallium nitride layer
US6060331Mar 29, 1999May 9, 2000The Regents Of The University Of CaliforniaMethod for making heterostructure thermionic coolers
US6064078May 22, 1998May 16, 2000Xerox CorporationFormation of group III-V nitride films on sapphire substrates with reduced dislocation densities
US6069021Mar 17, 1999May 30, 2000Showa Denko K.K.Boron phosphide buffer layers
US6100545Oct 13, 1998Aug 8, 2000Toyoda Gosei Co., Ltd.GaN type semiconductor device
US6120600Apr 13, 1998Sep 19, 2000Cree, Inc.Double heterojunction light emitting diode with gallium nitride active layer
US6121121Jul 27, 1999Sep 19, 2000Toyoda Gosei Co., LtdMethod for manufacturing gallium nitride compound semiconductor
US6139628Apr 8, 1998Oct 31, 2000Matsushita Electronics CorporationMethod of forming gallium nitride crystal
US6146457Jul 2, 1998Nov 14, 2000Cbl Technologies, Inc.Thermal mismatch compensation to produce free standing substrates by epitaxial deposition
US6153010Apr 9, 1998Nov 28, 2000Nichia Chemical Industries Ltd.Nitriding; forming recesses; masking
US6177688Nov 24, 1998Jan 23, 2001North Carolina State UniversityLow defect densities
US6180270Apr 24, 1998Jan 30, 2001The United States Of America As Represented By The Secretary Of The ArmyHeating gallium nitride bearing substrate layer according to predetermined time-temperature profile
US6201262Oct 7, 1997Mar 13, 2001Cree, Inc.Group III nitride photonic devices on silicon carbide substrates with conductive buffer interlay structure
US6255198Nov 17, 1999Jul 3, 2001North Carolina State UniversityMethods of fabricating gallium nitride microelectronic layers on silicon layers and gallium nitride microelectronic structures formed thereby
US6261929Feb 24, 2000Jul 17, 2001North Carolina State UniversityMethods of forming a plurality of semiconductor layers using spaced trench arrays
US6261931Jun 19, 1998Jul 17, 2001The Regents Of The University Of CaliforniaHigh quality, semi-insulating gallium nitride and method and system for forming same
US6265289Jun 7, 1999Jul 24, 2001North Carolina State UniversityThe defect density of the lateral gallium nitride semiconductor layer may be further decreased by growing a second gallium nitride semiconductor layer from the lateral gallium nitride layer.
US6291319Dec 17, 1999Sep 18, 2001Motorola, Inc.Method for fabricating a semiconductor structure having a stable crystalline interface with silicon
US6328796Feb 1, 1999Dec 11, 2001The United States Of America As Represented By The Secretary Of The NavySingle-crystal material on non-single-crystalline substrate
US6329063Dec 11, 1998Dec 11, 2001Nova Crystals, Inc.Method for producing high quality heteroepitaxial growth using stress engineering and innovative substrates
US6358770Jan 12, 2001Mar 19, 2002Matsushita Electric Industrial Co., Ltd.Method for growing nitride semiconductor crystals, nitride semiconductor device, and method for fabricating the same
US6380108Dec 21, 1999Apr 30, 2002North Carolina State UniversityPendeoepitaxial methods of fabricating gallium nitride semiconductor layers on weak posts, and gallium nitride semiconductor structures fabricated thereby
US6391748Oct 3, 2000May 21, 2002Texas Tech UniversitySurface free of amorphous silicon nitride; aluminum nitride layer grown by subjecting the silicon substrate to background ammonia followed by repetitively alternating the flux of 1) al without ammonia and 2) ammonia without al
US6403451Feb 9, 2000Jun 11, 2002Noerh Carolina State UniversityMethods of fabricating gallium nitride semiconductor layers on substrates including non-gallium nitride posts
US6420197Feb 23, 2000Jul 16, 2002Matsushita Electric Industrial Co., Ltd.Improved crystalline characteristics of algain nitride; strain reducing layer between layers of different thermal expansion coefficients; blue laser
US6440823Oct 26, 1998Aug 27, 2002Advanced Technology Materials, Inc.Low defect density (Ga, Al, In)N and HVPE process for making same
US6459712Jul 2, 2001Oct 1, 2002Hitachi, Ltd.Semiconductor devices
US6524932Sep 3, 1999Feb 25, 2003National University Of SingaporeMethod of fabricating group-III nitride-based semiconductor device
US6548333Jul 12, 2001Apr 15, 2003Cree, Inc.Aluminum gallium nitride/gallium nitride high electron mobility transistors having a gate contact on a gallium nitride based cap segment
US6610144Jul 19, 2001Aug 26, 2003The Regents Of The University Of CaliforniaMethod to reduce the dislocation density in group III-nitride films
US6617060Jul 2, 2002Sep 9, 2003Nitronex CorporationGallium nitride materials and methods
US6649287Dec 14, 2000Nov 18, 2003Nitronex CorporationGallium nitride materials and methods
US6707074Jul 2, 2001Mar 16, 2004Matsushita Electric Industrial Co., Ltd.Semiconductor light-emitting device and apparatus for driving the same
US6765240Aug 21, 2001Jul 20, 2004Cree, Inc.Bulk single crystal gallium nitride and method of making same
US20010008656Oct 21, 1997Jul 19, 2001Michael A. TischlerBulk single crystal gallium nitride and method of making same
US20010042503Feb 10, 1999Nov 22, 2001Lo Yu-HwaMethod for design of epitaxial layer and substrate structures for high-quality epitaxial growth on lattice-mismatched substrates
US20020074552Dec 14, 2000Jun 20, 2002Weeks T. WarrenGallium nitride materials and methods
US20020117681Feb 23, 2001Aug 29, 2002Weeks T. WarrenGallium nitride material devices and methods including backside vias
US20020117695Feb 23, 2001Aug 29, 2002Ricardo BorgesGallium nitride materials including thermally conductive regions
US20020187356Jul 2, 2002Dec 12, 2002Weeks T. WarrenGallium nitride materials and methods
US20030136333 *Jun 8, 2001Jul 24, 2003Fabrice SemondPreparation method of a coating of gallium nitride
US20050054132 *Sep 29, 2004Mar 10, 2005Nichia CorporationNitride semiconductor device and manufacturing method thereof
EP0514018A2Apr 16, 1992Nov 19, 1992AT&amp;T Corp.Method for making low defect density semiconductor heterostructure and devices made thereby
EP0852416A1Sep 17, 1996Jul 8, 1998Hitachi, Ltd.Semiconductor material, method of producing the semiconductor material, and semiconductor device
EP0942459A1Apr 9, 1998Sep 15, 1999Nichia Chemical Industries, Ltd.Method of growing nitride semiconductors, nitride semiconductor substrate and nitride semiconductor device
EP0951055A2Nov 10, 1998Oct 20, 1999Hewlett-Packard CompanyEpitaxial material grown laterally within a trench
EP1022825A1Feb 27, 1998Jul 26, 2000Sharp CorporationGallium nitride semiconductor light emitting element with active layer having multiplex quantum well structure and semiconductor laser light source device
WO1996041906A1Jun 13, 1995Dec 27, 1996Advanced Tech MaterialsBulk single crystal gallium nitride and method of making same
WO2000033365A1Nov 23, 1999Jun 8, 2000Eric P CarlsonFabrication of gallium nitride layers by lateral growth
WO2001027980A1Oct 11, 2000Apr 19, 2001Cree IncSingle step pendeo- and lateral epitaxial overgrowth of group iii-nitride layers
WO2001037327A1Oct 4, 2000May 25, 2001Robert F DavisPendeoepitaxial growth of gallium nitride layers on sapphire substrates
WO2001043174A2Dec 13, 2000Jun 14, 2001Univ North Carolina StateFabrication of gallium nitride layers on textured silicon substrates
WO2001047002A2Dec 13, 2000Jun 28, 2001Univ North Carolina StatePendeoepitaxial gallium nitride layers grown on weak posts
WO2001059819A1Aug 22, 2000Aug 16, 2001Robert F DavisMethods of fabricating gallium nitride semiconductor layers on substrates including non-gallium nitride posts, and gallium nitride semiconductor structures fabricated thereby
Non-Patent Citations
Reference
1Bykhovski, A.D. et al., Elastic strain relaxation in GaN-AIN-GaN semiconductor-insulator-semiconductor structures, J. Appl. Phys. 78(6):3691-3696, Sep. 15, 1995.
2Bykhovski, A.D. et al., Elastic strain relaxation in GaN-AIN-GaN semiconductor—insulator—semiconductor structures, J. Appl. Phys. 78(6):3691-3696, Sep. 15, 1995.
3Chichibu, S., et al., Appl. Phys. Left. 70(16), 2085-2087 (1997): Optical properties of tensile-strained wurtzite GaN epitaxial layers.
4Chu, T. L. et al., J. Electrochem. Soc. 118, 1200 (1971); Gallium nitride films.
5Dadgar, A. et al., "Metalorganic Chemical Vapor Phase Epitaxy of Crack-Free GaN on Si (111) Exceeding 1mum in Thickness," Jpn. J. Appl. Phy. 39:L1183-1185, Nov. 15, 2000.
6Dadgar, A. et al., "Metalorganic Chemical Vapor Phase Epitaxy of Crack-Free GaN on Si (111) Exceeding 1μm in Thickness," Jpn. J. Appl. Phy. 39:L1183-1185, Nov. 15, 2000.
7Edwards, N. V., et al., Appl. Phys. Lett. 73, 2808 (1998): Trends in residual stress for GaN/AIN/6H-SiC heterostructures.
8Guha, S. et al., "Ultraviolet and violet GaN light emitting diodes on silicon," Appl. Phy. Lett. 72(4):415-417, Jan. 26, 1998.
9Haffouz, S. et al., "The effect of the Si/N treatment of a nitridated sapphire surface on the growth mode of GaN in low-pressure metalorganic vapor phase epitaxy," Applied Physics Letters, 73(9):1278-1280, Aug. 31, 1998.
10Hirosawa et al., "Growth of Single Crystal AlxGa1-xN Films on Si Substrates by Metalorganic Vapor Phase Epitaxy," Jpn. J. Appl. Phys. vol. 32 (1993) pp. 1039-1042.
11JP 11040847, Toshiba Corp., Feb. 12, 1999, Abstract.
12JP 11145514, Toshiba Corp., May 28, 1999, Abstract.
13Lahreche, H. et al., "Optimisation of AIN and GaN growth by metalorganic vapour-phase epitaxy (MOVPE) on Si(111)," Journal of Crystal Growth, 217:13-25, 2000.
14Lei, T. et al., "Epitaxial growth of zinc blende and wurtzitic gallium nitride thin films on (001) silicon," Appl. Phy. Lett. 59(8):944-946, Aug. 19, 1991.
15Nikishin, S.A. et al., "High quality GaN grown on Si(111) by gas source molecular beam epitaxy with ammonia," Applied Physics Letters, 75(14):2073-2075, Oct. 4, 1999.
16Nikitina, I.P., et al., Diamond and related materials 6, 1524 (1997): Residual strains in GaN grown on 6H-SiC.
17Ohtani, A. et al., "Microstructure and photoluminescence of GaN grown on Si(111) by plasma-assisted molecular beam epitaxy," Appl. Phys. Lett. 65(1):61-63, Jul. 4, 1994.
18Osinsky, A. et al., "Visible-blind GaN Schortky barrier detectors grown on Si(111)," Applied Physics Letters, 72(5):551-553, Feb. 2 1998.
19Pearsall, Thomas P., Volume Editor, "Strained-Layer Superlatrices: Materials Science & Technology," Semiconductors and Semimetals, vol. 33, pp. 242-243, Department of Electrical Engineering, University of Washington, Seattle, Washington, Academic Press, Inc. 1991.
20Semond, F. et al., "GaN grown on Si(111) substrate: From two-dimensional growth to quantum well assessment," Applied Physics Letters, 75(1):82-84, Jul. 5, 1999.
21Seon, M. et al., "Selective growth of high quality GaN on Si(111) substrates," Applied Physics Letters, 76(14):1842-1844, Apr. 3, 2000.
22Takeuchi, T., et al., J. Cryst. Growth, Dec. 1991, vol. 115, (No. 1-4): 634-8.
23Tanaka, S. et al., "Defect structure in selective area growth GaN pyramid on (111)Si substrate," Applied Physics Letters, 76(19):2701-2703, May 8, 2000.
24Tran, C.A. et al, "Growth of InGaN/GaN multiple-quantum-well blue light-emitting diodes on silicon by metalorganic vapor phase epitaxy," Applied Physics Letters, 751(11):1494-1496, Sep. 13, 1999.
25Watanabe, A., et al., J Cryst. Growth 128, 391-396 (1993); The growth of single crystalline GaN on a Si substrate using AIN as an intermediate layer.
26Zhao, G.Y. et al., "Growth of Si delta-doped GaN by metalorganic chemical-vapor deposition," Applied Physics Letters, 77(14):2195-2197, Oct. 2, 2000.
27Zhao, Z.M. et al, "Metal-semiconductor-metal GaN ultraviolet photodetectors on Si(111)," Applied Physics Letters, 77(3):444-446, Jul. 17, 2000.
Classifications
U.S. Classification117/105, 117/84, 117/88, 117/102, 117/952, 117/89, 117/93
International ClassificationH01L33/00, C30B25/02, H01L21/205, C30B25/14, H01L21/20
Cooperative ClassificationH01L33/0075, H01L21/0254, H01L21/02378, H01L21/0262, C30B29/406, C30B29/403, H01L21/02381, H01L21/02458, C30B25/02, H01L21/0251
European ClassificationH01L21/02K4E3C, H01L21/02K4B1B1, H01L21/02K4C1B1, H01L21/02K4A1A2, H01L21/02K4A1A3, H01L21/02K4B5L7, C30B29/40B2, C30B25/02, C30B29/40B, H01L33/00G3C
Legal Events
DateCodeEventDescription
Aug 2, 2013FPAYFee payment
Year of fee payment: 4
Jan 4, 2011ASAssignment
Owner name: NAVY, SECRETARY OF THE UNITED STATES OF AMERICA, V
Effective date: 20080724
Free format text: CONFIRMATORY LICENSE;ASSIGNOR:CALIFORNIA, UNIVERSITY OF;REEL/FRAME:025630/0887